Still overheating

[Ray Ritchotte]

This is going to be a long post but I need some help.
Here is what I have done:
From my previous post my 150 Pro V tlrp was and still is overheating when I advance the throttle over 4300 rpm's.
I replaced both thermostats, took out and cleaned the pressure control valve, installed new impeller ,housing and gaskets.
Went to the lake and over heat indicater and horn came on. Motor went to idle rpm.
Came home took the thermostats out, took off the water intake screens, ran water through the thermostat housing from the hose and it ran out from the inlet. Put the hose on the water muffs over the removed intake screen and started up motor and both heads flowed good water from the thermostat housings. Next step I removed the water pressure control valve and cover and started up motor and good water flow comming from that area. Shut it down and ran water into the hose that is connected to the w/c/v or poppit and good flow of water comming out of the water intake area.
My neighbor who is a mechanic with Fed Ex brought his ohm meter home and he checked my over heat sensers and there is no resistance. (I assume that these sensers make contact when the motor over heats allowing current to go to the computor.) When not hot they stay open.
I am waiting for my new poppit valve kit to come in from boats .net.
The old one which I removed was clean and looked good to me but I am still going to replace it with the new type. "O" ring nice and smooth.
I don't know what else to do. Water is flowing every where like its suppose to do.
Ray

[jb123]

you DID replace plate under impeller, yes?
post results after prv
lastly you may need to pull and clean jackets

[mrv8outboard]

What have you changed just before your overheat issue? Anything at all? Install a water pressure gauge. Check for any sharp protrusions from the bottom or transom, even small things. Why? Because this can cause cavitation. I.E. Air bubbles in the water caused by a low pressure area boiling the water. If you can eliminate cavitation I would suspect the grommet at the top of the water tube or block cooling passages plugged or powerhead base gasket. Is the engine mounted too high? Simple first.

[jperconte]

I ran into a simlar problem on my Yami, I had to open the stat housing as you did, and remove the tell tale tube from the engine and flush the engine. This will allow more water to be removed from the engine with out restriction from the tell tale tube. Also, I used a power nozzle on the housing to apply forceful pressure in the stat house. (Home Depot run).
james

[Ray Ritchotte]

This is going to be a long post but I need some help.
Here is what I have done:
From my previous post my 150 Pro V tlrp was and still is overheating when I advance the throttle over 4300 rpm's.
I replaced both thermostats, took out and cleaned the pressure control valve, installed new impeller ,housing and gaskets.
Went to the lake and over heat indicater and horn came on. Motor went to idle rpm.
Came home took the thermostats out, took off the water intake screens, ran water through the thermostat housing from the hose and it ran out from the inlet. Put the hose on the water muffs over the removed intake screen and started up motor and both heads flowed good water from the thermostat housings. Next step I removed the water pressure control valve and cover and started up motor and good water flow comming from that area. Shut it down and ran water into the hose that is connected to the w/c/v or poppit and good flow of water comming out of the water intake area.
My neighbor who is a mechanic with Fed Ex brought his ohm meter home and he checked my over heat sensers and there is no resistance. (I assume that these sensers make contact when the motor over heats allowing current to go to the computor.) When not hot they stay open.
I am waiting for my new poppit valve kit to come in from boats .net.
The old one which I removed was clean and looked good to me but I am still going to replace it with the new type. "O" ring nice and smooth.
I don't know what else to do. Water is flowing every where like its suppose to do.
Ray

I just replaced the poppit valve with the new type. One thing I did notice is that the spring on the new poppit has more strenght to it. The old one was easier to compress than the new one. I will go to the lake next week to see if it works.
Ray

[Ray Ritchotte]

What have you changed just before your overheat issue? Anything at all? Install a water pressure gauge. Check for any sharp protrusions from the bottom or transom, even small things. Why? Because this can cause cavitation. I.E. Air bubbles in the water caused by a low pressure area boiling the water. If you can eliminate cavitation I would suspect the grommet at the top of the water tube or block cooling passages plugged or powerhead base gasket. Is the engine mounted too high? Simple first.

Water pressure gauge reads 18 -20 psi.
What grommit is it ? Idon't see one in the parts breakdown.There is one in the new housing that the tube goes into. Is there another one onesome where ??